Kiso (木曽町; kiso-machi) is larger and considerably more developed than Magome, Tsumago or Narai. There's a full-on town here around Kiso-Fukushima Station, but there's also the atmospheric historic district of Ue-no-dan down below the station. Kiso was an important checkpoint on the Nakasendō, and in times requiring high security the road would be blocked off at Fukushima-juku.
These days, Kiso-Fukushima is the jumping-off point for hikers and sightseers heading to Ontake-san, Japan's second-highest volcano (3067m). In 2005 the town of Kiso-Fukushima merged with three smaller villages to form the Kiso District, with the administrative centre and JR station about mid-valley, north of Tsumago and Magome and south of Narai.